Improvement in bridge-walls for furnaces



J. MAILER'. Bridge-Wall forl Furnaces.

No. 219,283. Patented sept. 2,1879.

-spondin g parts.

UNITED ti'IA'IEs PA'IEN'I OEEICE JOHN MAILER, OE PACHECO, CALIFORNIA.

IMPROVEMENT IN BRIDGE-WALLS FOR FURNACES.

YSpecification forming part of Letters Patent No. 219,283., dated September 2, 1879 5 application led t January 27, 1879.

.of California, have invented a new and Improved Bridge-fall for Furnaces,'of which thefollowing is a specification.

Figure l is an upright sectional View show-` ing boiler, bridge-wall, and attachments. Fig.

'2 is a section on line .r x.

f Similar letters `of reference indicate correlhisinvention has for its object the placing fof a movable bridge-wall in a boiler-furnace, in order to contract the area of outlet from l the tire-surface to the boiler-fines.

tween them. This space is filled with clay,

plaster, asbestus, or other refractory and nonconducting material, as shown at b'.

' The bridge-wall, or damper7 as it may be called, is preferably made a few inches narrowcr and shorter than the tire-surface. The lower end is made to rest upon or is fulcrumed upon the grate-bars or the grate-bar bearings To the other end a chain, F, is attached and drawn through one of the boiler-fines, as shown. That part of the chain most exposed to the action of the fire is enveloped by a sleeve, E. which consists, preferably, ot' a metallic cylinder filled in with some good nonconducting substance.

Qrdinarily this bridge-wall will be retained in position by resting (leaning) upon the sup- I ports D D, as shown in drawings, for when it is in this position a sufficient draft-area for the satisfactory combustion of most. fuels is left around its' upper end.

By removing the supports D D the bridgewall can be adjusted in a lower position and' held there by the chain F, and the chain also serves to adjust and retain itat any other elevation.

Another method of supporting and adjusting theibridge-Wall is to insert thimbles or short pieces ofV tubing through the sides of the boiler-furnace, just opposite to each other, and to pass through these a baror tube (shown at K) upon which the wall shall rest. A wedge, L, is in such case used for adjusting the bridgewall in position. When a tube is used for this purpose I keep it from becoming too hot and yielding by passing air or water through it. This arrangement is especially designed for application to boiler-furnaces wherein straw, tan-bark, or other substance is burned whose better combustion may be insured by a hotter furnace or by longer retention in the furnace. Itis obvious that so soon as the guard or bridge-wall becomes heated it will radiate heat upon the fuel on the grate as well as upon the escaping smoke and gases, and thus supply in most instances vthe small increment of heat that is required for their complete combustion.

The effect which the guard will have in retarding the escape of the smoke, gases, and particles of burning or unburned fuel from the fire-place, and in thus giving them a longer exposure to heat, is` also very apparent..

Having thus described my invention, I claim as new and desire to secure by Letters Patent- The bridge-wall O, fulcrumed as shown, and

Aadjustable at different angles of inclination in the furnace, between the grate and the boilerlilies, by means -of the chain F, substantially as shown and described, and for the purpose set forth.

J OHN MAILER.

Witnesses:

ANDREW LEEs PRINGLE, WILLIAM WA'rsoN. 

